This disclosure is related to the subject matter of U.S. Pat. No. 4,758,156 issued Jul. 19, 1988, to William B. Johnson, entitled "A Tool For Use In Applying Filler Material To An Endodontically Prepared Root Canal" and U.S. Pat. No. 4,894,011 issued Jan. 16, 1990, to William B. Johnson, entitled "Appliance For Use In Applying Filler Material To An Endodontically Prepared Root Canal," both of which patents are incorporated herein by reference.
As pointed out in the two above-identified U.S. patents, the conventional technique for preforming endodontic therapy on teeth is time consuming and often does not adequately ensure that the entire canal system is filled with the filler material. Experience has shown that it is not possible in all cases to remove all pulpal remnants and contaminants from a root canal with currently used preparation techniques. If the pulpal remnants and contaminations are thoroughly entombed in the repair material, the endodontic therapy will be successful. If the remnants and contaminants are not thoroughly entombed, there is high probability of failure of the endodontic therapy. Complete entombment of the remnants and contaminants requires complete obturation of the canal system.
The general technique employed by dentists in the United States and throughout the world prior to the above two mentioned U.S. patents consisted of packing a filler material, such gutta-percha, into the endodontically prepared root canal.
The technology employed in the above two mentioned U.S. patents has improved the practice of filling endodontically prepared root canals by making use of an obturator body having filler material thereon. After the root canal is prepared, the obturator body is inserted into the root canal, carrying with it, on the exterior surface thereof, filler material. The shaft portion of the obturator body and filler material remain in the prepared canal to more effectively fill the canal and entomb any remaining pulpal material or contaminants, and such system has been commercially successful and widely practiced by dentists and endodontists.
The obturator body shaft portion functions as a condenser of the filler material and assists in plugging the root canal. Further, the obturator body shaft portion remaining in the root canal helps reduce the effect of shrinkage of the filler material.
The present disclosure is of an improved obturator body that is particularly characterized by improved means of enabling a dental practitioner to accurately position the body shaft portion to the proper depth in a root canal by the provision of effective length indicators.